Lamp socket



oct. 12, 1937. D. B. MCRAE 2,095,825

LAMP SOCKET Filed Aug. 18, 1934 2 Sheets-Sheet 1 Daniel B. MQRae;

Patented Oct. 12, 1937 UNITED STATES PATENT OFFICE LAMP SOCKET Jersey Application August 18, 1934, Serial No. 740,468

3 Claims.

This invention relates to lamp sockets and particularly to sockets for incandescent lamps especially adapted to receive lamps of relatively high wattage.

One object of my invention is to provide a lamp socket which can withstand high heat without having a tendency to become soldered to the tip of a lamp base. Another object of my invention is to provide a lamp socket with a spring contact member made of a metal resistant to solder. Another object of my invention is to.` provide a lamp socket in which the members which contact with the lamp base are made of metals which do not solder readily, and other objects will appear from the following specication, the novel features being particularly pointed out in the claims at the end thereof.

Coming now to the drawings wherein like reference characters denote like parts throughout:

Fig. 1 is a part section and part side elevation of a lamp and lamp socket, the lamp socket being constructed in accordance with and embodying a preferred form of my invention.

Fig. 2 is a plan view of theA lamp socket shown in Fig. 1.

Fig. 3 is a fragmentary detail sectional view of a spring contact which may be used in a modified form of my invention.

Fig. 4 is a sectional view of a lamp socket constructed in accordance with still another embodiment of my invention.

In lamp sockets particularly adapted to receive lamps consuming a large number of watts, it frequently happens that the lamp socket becomes extremely warm, and this tends to melt the solder tip on the base of the lamp which forms one contact usually with a spring member in the lamp socket.

Many of the high wattage lamps are used in reflectors and in lamp housings which, in spite of their forced ventilation, do not permit sufcient air to circulate about the lamp socket to prevent this part from becoming overheated.

Where the solder tip on the lamp base melts with the sockets now in use, the spring which is adapted to contact with this tip is ordinarily made of brass and the lamp becomes soldered to this spring. When the lamp is removed, it frequently breaks, and in anyevent considerable diiculty is caused in removing the lamp, since the spring is soldered so tightly to the tip that a new lamp socket is required. It is primarily to overcome these difiiculties that the lamp socket which will be hereinafter more fully described was designed.

Referring to Fig. 1, in which a preferred embodiment of my invention is shown, I prefer to construct the lamp socket or base I of an insulating material, such as porcelain, glass, or any of the Well-known type of moldable materials used for this purpose. This base may include an annular upstanding portion 2 having an opening 3 in which the lamp contacts 4 and 5 are mounted.

Contact 4 may consist of a tubular sleeve 6 threaded to receive a lamp base I of the usual type. The interiorly threaded sleeve 6 Yis electrically connected by a wire 8 to the contact 9 to which a power wire may be attached by the screw I in the usual manner.

The second contact is a spring Contact, the base of which II is electrically connected by a wire I2 to a Contact I3 to which a power wire may be attached by the screw I4.

It is the spring member 5 which causes the most difficulty in becoming soldered to the tip of a lamp, so that this member I prefer to make of a metal which has the property of resisting solder. Such metals are well known and may be, for example, aluminum, Duralumin, and most other aluminum alloys, zinc, Monel, and other metals which can only be soldered with difculty. Some of these metals can only be soldered by bringing up the metal to an extremely high temperature and utilizing a special solder and special flux. Where I refer in the specification and claims to a metal which is resistant to solder, I mean a metal which is resistant to the ordinary methods of soldering with the well-known types of solder and flux.

As indicated in Fig. 1, the lamp I5, which may be of the type having a series of coils I 6, may be provided with a base 'l having a threaded area I'I adapted to screw into the interiorly threaded socket 6. This forms one lamp contact. The other is a portion I8 preferably annular in shape, which is provided with a contact I9 adapted to engage the spring 5. In many lamps this contact I8 is made of solder, and it is this part of the lamp which frequently becomes accidentally soldered to the usual type of brass spring. However, when the spring has been made of a metal which is resistant to solder, such as aluminum, even if the solder tip I9 does melt, it will run off of the aluminum and not become attached to it. 'Ihus, if the lamp should become overheated to such an extent that the tip I9 melts, the lamp can still be removed from the socket Without destroying either the lamp or the socket.

It is well known, of course, that aluminum does not form a satisfactory spring, and if desired the spring can be constructed as shown in Fig. 3. In this gure the spring head 25 is preferably provided with a downwardly extended forming 26 and the spring arm 21 is bent to form the base part 28 at 29. The base 28 is preferably provided with a forming 30 so that the formings 26 and 30 may support both ends of a coiled spring 3|, this spring being of suilicient strength to hold the contact 25 awayfrom the base 28 and to overcome the inertia of the aluminum spring member 21.

It is not necessary, however, to form the contact 5 of aluminum and use a separate spring 3| as above described because some of the aluminum alloys are suiliciently springy for use without an additional spring. Y

In Fig. 4 I have illustrated another embodiment of my invention illustrating in this figure a lamp base vwhich is frequently used in apparatus using special purpose lamps, such as projection lamps, floodlight lamps, and the like. In accordance with this embodiment of my invention, the socket 40 is of any desired insulating material and carries a pair of contacts 4| and 42 for the lamp, the rst of these being a cylindrical member having one or more bayonet slots 43 to'receive a pin or pins projecting outwardly from a lamp base and the second contact42 being of any wellknown type which is adapted to be compressed when the lamp base is inserted in the socket.

While I have illustrated several preferred forms of my invention, it is to be distinctly understood that my invention is not limited to the use of the lamp sockets illustrated, but is adapted for use in any lamp socket which is equipped to receive lamps of known types in which one of the lamp contacts is made of solder.

While I have found it necessary to provide the spring contact of the lamp socket of a metal which resists solder, it is frequently useful to provide the other contact, which may be the threaded contact member 6 of Fig. 1 or the cylindrical contact 4| of Fig. 4, also of metal adapted to resist solder. This is particularly useful in cases where the lamp socket is to be used in a position other than vertical. If used in a hori- Zontal position, it occasionally happens that the solder tip I9 will melt and run down the edge of the lamp base so that it may solder the interengaging threaded portions of the lamp and socket together. While this does not occur nearly so often as soldering the tip of the lamp to the spring contact, it nevertheless does occur and can readily be prevented by making both contacts of the lamp socket of a metal resistant to solder.

I therefore contemplate as included within the scope of my invention all such lamp sockets as may come within the terms of the following claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a lamphouse for projection apparatus adapted to receive high power lamps, the combination with a socket for the lamp including an insulating base, contacts carried by the base spaced from each other, at least one contact comprising a conducting material having the property of being resistant to solder whereby heat generated by the lamp in the lamphouse cannot cause the lamp and contact to adhere.

2. In a lamphouse for projection apparatus adapted to receive high power lamps, the combination with a socket for the lamp including an insulating base, contacts carried by the base spaced from each other, at least one contact being made of aluminum whereby the heat generated by the lamp in the lamphouse cannotV cause the lamp and contact to adhere.

3. In a lamphouse for projection apparatus adapted to receive high power lamps, the combination with a socket for the lamp including an insulating base, contacts carried by the base spaced from each other, at least one contact being made of an aluminum base metal whereby the heat generated by the lamp in the lamphouse cannot cause the lamp and contact to adhere.

DANIEL B. MCRAE. 

